Apparatus for flame spraying powder



Nov. 4, 1969 J. F. FLEISCHHACKER ET AL APPARATUS FOR FLAME SPRAYING POWDER s Sheets-Shet i W m N Q% N M N J I ..l .l x/ i p H mm. MN awn Q UQR RV mm NV Java/Pm;

Nov. 4, 1969 J. F. FLEISCHHACKER ET AL 3,476,320

APPARATUS FOR FLAME SPRAYING POWDER 3 Sheets-Sheet Filed May 9, 1967 FIG. 3 4

Jrraawezf J. F. FLEISCHHACKER .ET AL 3,476,320

APPARATUS FOR FLAME SPRAYING POWDER Nov. 4, 1969 3 Sheets-Sheet mu nmhuhm m2 ow Q\\ Z VAFZZZZZ ream K T Kauai-107a flmymflrrozwsrs Evy/ United States Patent O US. Cl. 239-85 41 Claims ABSTRACT OF THE DISCLOSURE Powder spray torch apparatus having a conventional torch body and a powder spray attachment that includes a powder hopper from which powder flows over a powder baflle, through an axially compressible metering valve, a resilient valving tube having a rigid tubular support therearound, and to a clearance space where the powder is aspirated into a mixed gas stream. Vent apertures are provided between the baffle and hopper outlet, while in one embodiment a transverse resilient sleeve is abuttable against the valving tube; and in the second embodiment an annular thrust member is provided between the metering valve and valving tube, and the tubular support has a keyway slot that cooperates with the plunger to prevent the tubular support rotating.

BACKGROUND OF THE INVENTION The apparatus of this invention is used for spraying plastic or metallic powder onto a surface to form a coating thereon; and in particular to controlling the flow of powder, mixing powder with the gas stream and minimizing back flashes. Prior art patents include US. Patent 3,226,028 to Schilling and US. Patent 2,957,630 to Lamb.

Problems encountered with prior art powder torches include dangers resulting from flash back and controlling the rate of spraying the powder. For example, under commonly encountered conditions, mixed gas flows into the powder hopper and thereby creates a potentially dangerous condition, and the rate of flow of powder can be only readily controlled to provide a given maximum rate of powder flow and a zero flow rate, but not permitting easily changing the flow rate between these extremes and at the same time permit readily blocking the flow of powder. In order to minimize problems of the aforementioned nature and to provide a powder torch of more durable construction, this invention has been made.

SUMMARY OF THE INVENTION Powder spray torch apparatus that includes a diffuser to compensate for back pressures resulting from restrictions downstream of the injector and more thoroughly mixing mixed gases and powder, axially compressible metering valve mechanism for selectively varying the rate of powder flow together with indicating mechanism; a baffle, vent apertures and a shield for venting gas and directing any back flash forces that may occur upwardly along the exterior surface of the hopper; and valving tube shut ofi' mechanism that includes a transverse sleeve abuttable against a valving tube, or a tubular support having a keyway slot that even in a plunger retracted position cooperates with the plunger to maintain proper angular alignment between the plunger and the tubular support.

One of the objects of this invention is to provide a new and novel powder torch for minimizing the likelihood of occurrence of flash back. Another object of this invention is to provide a new and novel torch for directing any back fire that may occur away from the operators hand to minimize the chance of injury to the operator. An additional object of this invention is to provide a powder 'ice torch having new and novel mechanism for directing flash back forces, that may occur, primarily outwardly of the powder hopper.

A further object of this invention is to provide a powder torch having new and novel mechanism for controlling the flow of powder from the powder hopper to the gas stream in the torch. A still further object of this invention is to provide new and novel valving mechanism for permitting powder flow and discontinuing the powder flow from the powder hopper to the torch gas stream. In furtherance of the last mentioned object, another object of this invention is to provide valving mechanism of a construction that will withstand longer periods of usage than prior art torches and minimizes the chances of breakdown of said mechanism. An additional object of this invention is to provide in a powder torch, new and novel valving mechanism for selectively metering the rate of flow of powder from the powder hopper to the torch gas stream.

It is still another object of this invention to provide new and novel mechanism for aspirating powder from the powder hopper and entraining powder in a mixed gas stream of a torch. Still another object of this invention is to provide a new and novel powder torch having a diffuser for dispersing the powder that is being entrained in the gas stream, and compensate for back pressures resulting from restrictions downstream of the injector.

Other and further object are those inherent in the invention herein illustrated, described and claimed, and will become apparent as the description proceeds.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is illustrated in the drawings in which the same numerals refer to corresponding parts and in which:

FIGURE 1 is a fragmentary view, part in side elevation, part in vertical cross section and part in schematic, showing the first embodiment of the powder torch of this invention;

FIGURE 2 is an enlarged vertical cross sectional view of a portion of the structure illustrated in FIGURE 1, said view showing the powder shut off valve in a closed position;

FIGURE 3 is a still further enlarged, transverse cross sectional view of the powder shut off valve, said view being generally taken along the line and in the direction of arrows 3-3 of FIGURE 2 other than the powder shut off valve as illustrated in an opened condition;

FIGURE 4 is an enlarged transverse cross sectional view of the mechanism for directing any backflow of mixed gases and backfire flames radially outwardly of the powder hopper and upwardly alongside the' exterior surface of the hopper, said view being generally taken along the line and in the direction of arrows 44 of FIGURE 2;

FIGURE 5 is a cross sectional view of the mechanism for diffusing and venting any mixed gases and backfire flames adjacent the hopper outlet to the ambivalent atmosphere, said view being generally taken along the line and in the direction of the arrows 5-5 of FIGURE 2;

FIGURE 6 is a still further enlarged side elevational view of a portion of the powder shut off valve structure of the first embodiment;

FIGURE 7 is a fragmentary front view of a structure for controlling the metered rate of flow of powder generally taken along the line and in the direction of the arrows 77 of FIGURE 1;

FIGURE 8 is a cross sectional view of a portion of the structure illustrated in FIGURE 2;

FIGURE 9 is a further enlarged fragmentary view of a portion of the structure of FIGURE 1, said view showing the diffuser and adjacent structure;

FIGURE is a fragmentary view, part in side elevation and part in vertical cross section of a powder spray torch illustrating the second embodiment of the invention, a portion of the powder hopper being broken away;

FIGURE 11 is an enlarged vertical cross sectional view of a portion of the structure illustrated in FIGURE 10;

FIGURE 12 is a still further enlarged, transverse cross sectional view of the powder shut off valve mechanism, said view being generally taken along the line and in the direction of the arrows 1212 of FIGURE 11 other than the powder shut off valve mechanism is illustrated in an opened condition;

FIGURE 13 is an enlarged cross sectional view of the mechanism for diffusing and venting any mixed gases and backfire flames adjacent the hopper outlet to the ambivalent atmosphere, said view being generally taken along the line and in the direction of the arrows 1313 of FIGURE 11;

FIGURE 14 is an enlarged transverse cross sectional view of the mechanism for directing any mixed gases and back fire flames generally radially outwardly of the powder hopper and upwardly alongside the exterior surface of the hopper, said view being generally taken along the line and in the direction of the arrows 14-14 of FIGURE 11; and

FIGURE 15 is a somewhat diagrammatical illustration of the gas venting feature of both embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGURES 1-9, which illustrate the first embodiment of the invention; and in particular to FIGURE 1, there is illustrated, partly in schematic, a fragmentary portion of a conventional torch body, generally designated 11. The torch body 11 has bore 12 that in part forms a portion of the oxygen passageway 13 through the torch body. A valve 14 is provided in passageway 13 for controlling the supply of pressurized oxygen to bore 12.

The torch body is also provided with a combustion supporting gas passageway 15 that at one end opens to an annular groove 16 that in turn opens to bore 12. A valve 16 is provided in passageway 15 for controlling the supply of combustion supporting gas such as acetylene to said passageway.

Extended into the forward end portion of the bore 12 is a mixed gas conducting member 17, said member having a shoulder cooperating with a shoulder formed in the bore 12 to limit the amount of extension of said member into said bore.

A nut 28 has a reduced diameter annular portion threaded into the forward end portion of bore 12 to abut against a shoulder of member 17 to retain member 17 against the aforementioned bore shoulder. The rearward end of member 17 is internally threaded to receive a nozzle 18 having a conical tip received in a corresponding shaped bore 19 in said member. The wall of the bore 19 is spaced from the adjacent wall of the conical tip to provide a fluid passageway 20 communicating with the rearward end of bore 23 that is in the member 17 and also to communicate through radial apertures 26 that in turn open to an annular groove in member 17 to open to groove 16.

The nozzle has a bore that at one end opens to bore 12 and at the opposite end opens to the fluid passageway 20 adjacent the juncture thereof with bore 23. As may be noted from FIGURE 1 there is provided an O-ring on member 17 on either axial side of groove 16 to form a fluid seal with the torch body.

The forward portion of member 17 terminates within an intermediate portion of bore 30 of an adapter 32, an axially intermediate portion of member 17 being threaded to form a threaded connection with the rearward end portion of the adapter. The adapter 32 has an internal 4 annular flange 30a in abutting relationship with the forward end of a diffuser 31 that is also located in bore 30.

The forward end portion of member 17 has a conical tip that at its outer radial portion abuts against the correspondingly shaped rear end portion of the diffuser 31. The last mentioned conical tip and the adjacent portions of the diffuser cooperatively formed a passageway 36 surrounding the forward end portion of said tip and that opens into the space axially between a bore 33 and a bore 29. That is, the mixed gas conducting member has a reduced diameter bore 29 that at one end opens to the forward end of bore 23 and at the opposite end opens through the forward portion of passageway 36 to the short axial length cylindrical bore 33 which is of a substantially larger diameter than bore 29. The forward end of bore 33 opens into the rearward end of the frustoconical shaped mixing bore 34, bore 34 diverging in a forward direction. Bore 34 in turn opens to the cylindrical bore through flange 30a, the maximum diameter of bore 34 being substantially the same diameter as the bore in flange 30a.

Rearwardly and radially outwardly from the opening of the passageway 36 to bore 33, said passageway opens to a radial extending bore 37 in member 31. Axially rearwardly of bore 37 and passageway 36, an O-ring 38 is provided in a groove of member 17 to form a fluid seal between said member and the inner peripheral wall of adapter 32. A coupling 39 is threaded on the forward end portion of adapter 32 to retain an enlarged diametric flange of adapter 40 in abutting relationship with the forward end of the adapter 32. O-rings provide a fluid seal between the adapters 32, 40. The adapter 40 has a central bore 400. of slightly smaller diameter than the bore in flange 30a that at one end opens to the last mentioned bore and at the other end opens to the tip passageway 42 in the torch tip 43. The rearward end of the tip 43 is threaded into the forward end portion of adapter 40.

The adapter 32 mounts a hopper mounting body 46 which is in surrounding relationship thereto. A nut 47 is threaded on the forward end portion of adapter 32 in abutting relationship with the forward edge of body 46 for retaining a body shoulder 48 in abutting relationship with a shoulder provided on adapter 32. The hopper mounting body has a bore 49 that at one end opens to a bore 50 in the adapter 32, bore 50 in turn opening into bore 37. The opposite end of bore 49 opens to one end of bore 51 in boss 46b of body 46 while the opposite end of bore 51 in turn opens to one end of bore 52 in the annular, reduced diameter threaded end portion 46a of body 46. As may be noted from FIGURE 2, bore 52 is of substantially larger diameter than bore 51 while bore 51 in turn is substantially larger in a diameter than bore 43 and bore 49 is of substantially larger diameter than bore 50. The central axes of bores 49, S0, 51 and 52 are inclined rearwardly and upwardly and are coextensive with line H-H.

Annular portion 46a in turn threadedly mounts one end portion of a sleeve 53 such that the central elongated axis of the sleeve extends at an angle to be inclined downwardly and forwardly relative the direction of elongation of adapter 31 and diffuser 31, i.e. the sleeve central axis is coextensive with a portion of the line H-H of FIG- URE 1.

A generally upper end portion of the sleeve is beveled at 53b to converge in a downward direction and receive the outlet end portion of a powder carrying hopper 55, the hopper being mounted on said sleeve. The hopper includes a main body portion 550 and a cover 55a threadedly mounted on portion 55c, the cover being provided with a vent aperture 55b. The portion 550, other than for the portion the cover threadingly engages, is conical shape and converges in a downward direction to extend a substantial distance into sleeve 53 toward adapter 32. The hopper also includes a generally cylindrical outlet 55d that is integrally joined to the lower end of body portion 550. As may be noted from the drawings, the outside diameter of portion 55d is several times less than the inside diameter of the inner peripheral wall portion 53a of said sleeve.

The sleeve is provided with several radially extending apertures 56 that open through the inner peripheral wall 53a axially intermediate cylindrical portion 55d and the beveled surface 5312 that abuts against the hopper portion 53c and is attached thereto by, for example, welding or a threaded connection. The diameter of each of the apertures 56 is preferably about the same or larger than the inside diameter of hopper cylindrical portion 55d. The exterior portion of the sleeve from axially inwardly of apertures 56 to the upper end thereof is cut away to provide an annular space 57 radially intermediate the upper end portion of the sleeve and the cylindrical shield 58 that forms a close fit with the remaining exterior surface portion of the sleeve.

Mounted within bore 49, 51 of the hopper mounting body is a resilient valving tube 60, said tube in a relaxed condition having a constant internal diameter. Tube 60 has a greater axial length than its maximum outer diameter, said tube having a lower end portion 60a of a reduced external diameter that forms a sealing fit with the inner peripheral wall defining bore 49. The lower edge of portion 6021 forms a sealing fit with adapter 32 with the interior of the tube opening directly to bore 50. The inner diameter of the tube is substantially the same as the diameter of bore 50. The main body portion 60b of the tube is mounted within a tubular support 61 of, for example, metal, such that portion 6% extends axially beyond the opposite ends of said support. The end portions of the main body 6011 form a sealing fit with the adjacent inner peripheral wall portion defining bore 51 while the shoulder formed at the juncture of portions 60a and 60b seats against the shoulder formed by bores 49 and 51. That is, the support 61 retains main body portion 60b in sufiicient compression such that the axial outer end portions thereof extend radially outwardly beyond the exterior of the support. The support is also provided with a cut out 61a that in rear elevation is of a generally rectangular shape.

The upper edge of the valving tube abuts against the lower edge of the resilient, annular metering valve member 63 in fluid sealing engagement therewith. Also the lower surface of the metering valve member abuts against the shoulder formed by bores 51 and 52. Further, the metering valve has a central powder passageway 64 that at one end opens to the passageway in the valving tube, then converges along portion 64a in an upward direction to a substantially constant diameter intermediate portion 64b, and from said intermediate portion diverges in an upward direction along 64c to open into the reduced di ameter portion 66a of bore 66 of the bafiie mount 67. When the metering valve is not being axially compressed, the diameter of the portion 640 of bore 64 opening to bore 66 is substantially larger than bore portion 66a while likewise the diameter portion bore 64 that opens to the interior of the valving tube is substantially larger than the inner diameter of said tube. The intermediate portion of the metering valve in a non-axially compressed condition has an internal diameter that is about the same as the inner diameter of reduced diameter portion of bore 66 and the inside diameter of the valving tube.

The baifie mount has a reduced diameter portion 67a that extends within bore 52 in abutting relationship with the top surface of the metering valve, the main body portion 67b of the bafiie mount overlaying the upper edge of the annular portion 46a. Further, the main body portion of the baffle mount is threadedly connected to the sleeve 53 axially intermediate body portion 46a and the inner peripheral wall portion 53a of the sleeve. The sleeve has a shoulder at the lower terminal edge of wall portion 53a that bears against the upper annular edge of portion 671). Accordingly when the sleeve is threaded relative the hopper body mount in an appropriate direction, the bafiie mount is forced in a generally downward direction (direction of arrow 69 which extends parallel to line HH) whereupon the metering valve is axially compressed and thereby reduces the cross sectional area of the minimum diameter portion of bore 64.

The bafile mount in addition to having reduced diameter bore portion 66a, has an intermediate frusto conical bore portion 66b with a minor base opening to bore portion 66a and a major base opening to cylindrical bore portion 660. A baflle 70 has a lower, generally cylindrical portion 70a forming a close fit with bore portion 660 in seating against the shoulder of the baffle mount formed by the juncture of bore portions 66b and 66c and is press fitted in the baflie mount. The baflie also has a conical portion 70b that extends axially above portion 70a with the tip of said conical portion being centrally axially aligned with reference to the axial line HH that extends coextensive with the central axis of reduced diameter portion 55d of the hopper and the central axis of bore 49. The outer peripheral portion of the bafiie is provided with a plurality of cut outs that open to the baflie mount and provide powder passageways 71 to permit powder flow from outlet 55d to bore portion 6612 (see FIGURES 4 and 8). As may be noted from FIGURES 2 and 8, the smallest transverse dimension between diametrically opposed passageways 71 is substantially greater than the inside diameter of hopper outlet 55d and the tip of the conical point is substantially axially spaced from said outlet.

Referring now to FIGURES l3, the hopper mounting body includes a cutout 76 that opens to bore 51 and rearwardly through said body. Extending transversely through said cutout is a metal valve pin 77, said pin at its opposite ends extending through and being mounted by legs 78:: of the handle 78. The handle has a web 78b joining said legs and is provided with a notch 78c, such that the legs extend along opposed upwardly extending surfaces of the body 46. Mounted on the pin 77 in surrounding relationship thereto is a resilient pin sleeve 79, said sleeve extending within cutout 76. Advantageously sleeve 79 is made of the same material as valving tube 60.

The legs of the handle extend downwardly along opposite transverse sides of the hopper mounting body to a lower elevation than the adapter 32, the lower end portion of the handle being pivotally connected to the body 46 by a pivot member 80 that is extended through the hopper mounting body 46.

The handle mounts pin 77 and thereby sleeve 79 for arcuate movement from a position that sleeve 79 barely engages the valving tube such as is illustrated in FIG- URE 3 to a position that sleeve 79 squeezes the valving tube shut so no powder can flow therethrough (see FIG- URE 2). That is, the size and shape of the hopper mounting body cutout 76, the size and shape of the support sleeve cutout 61a, and their relative locations are such that sleeve 79 may be arcuately moved by the handle between the two aforementioned positions relative the valving tube. The axial height X of the cutout 61a is only slightly greater than the outside diameter of the pin sleeve. In the valving tube closed position, the pin sleeve 79 bottoms on the lower edge 61a of the support sleeve to provide for a poppet type valve action. Applicants have found that utilizing a resilient pin sleeve, for example, made of rubber, that blowout of the valving tube is substantially minimized in the valving tube shut off position from that which would occur if a metal pin Were to bear directly against the valving tube. Additionally by using a resilient pin sleeve, the shut off valving structure has no points of substantial wear such as would occur if a plunger were utilized, nor are any permanent indentations made in the valving tube on which powder may lodge to cause powder jams.

A spring clip 84 at one end is secured in the body 46 and has an opposite end bearing against the web portion of the handle for resiliently urging the handle toward a valving tube shut off position. The spring clip has spring characteristics such that when no manual pressure is applied to the handle, the in sleeve 79 squeezes the valving tube such that no powder can flow therethrough.

On the opposite side of the powder entraining section from the hopper, the hopper body has a forwardly and downwardly extending boss for mounting a rod 85. The central axis of the rod extends along the line H-H that passes through the central axis of the hopper outlet 55d.

Referring now in particular to FIGURE 7, the hopper body boss portion 4612 has one end of a pointer 87 fastened thereto by, for example, a screw, said pointer extending upwardly into the notch 88 (rectangular in front elevation with no lower edge) provided in the lower end portion of the tubular shield 58 and resiliently hearing against sleeve 53. Along the upper edge 88a of the notch there are provided a plurality of equally circumferentially spaced indicia 89. By turning the shield and sleeve 58 in the appropriate direction (due to the threaded connection of the sleeve to the body portion 46a), the sleeve will move axially relative the axis HH to axially compress the metering valve 63 and thereby reduce the minimum cross sectional area of the bore 64. The indicia 89 serves as an indication of the degree of axial compression of the metering valve and thus the rate of powder flow when the torch is being used. At the time of the initial assembly of the torch of this invention, the sleeve 53 is sufficiently threaded on annular portion 46a to have the baflle mount bear against the metering valve togive proper axial compression and thence the shield 58 is aflixed to the sleeve so that the notch edges 88b will be properly located relative the pointer 87 with the pointer extending in said cutout between said edges. Accordingly, within the limits of the circumferential spacing of the vertical edges 88b of the notch, the shield may be rotated from one angular position that one vertical edge 88b abuts against one side of the pointer 87 to a position that the other vertical edge 88b abuts against the opposite side of the pointer and thereby provide a limited range of adjustment of the minimum diameter opening of bore 64b of the metering valve to thus, within limits, control the rate of flow of the powder through the metering valve.

To facilitate the relative angular alignment of the adapter 32 with the hopper body, an exterior surface of the adapter is contoured as a flat area extending from along the upper surface of the pivot pin 80. Thereafter with the adapter and diffuser aligned, bores 50 and 37 are drilled to intersect passageway 36.

The structure of the first embodiment of the invention having been described, the structure of the second embodiment, generally designated 100, will now be described in particular with reference to FIGURES -14. Insofar as the portion of the second embodiment that is not illustrated, it is the same as the first embodiment. That is, the second embodiment includes a gas conducting member 101, which has a right hand portion as viewed in FIG- URE 10, that is of the same construction as gas conducting member 17. Member 101 is secured by a nut 28 to conventional torch body (not shown). The forward end of the gas conducting member is threadably extended into an adapter 32 and has a forward enlarged diameter bore portion in which the reduced diameter portion of injector nozzle 104 is seated. The injector nozzle has a forward, generally conical end portion 104a, a bore portion 105 that opens to the forward end of bore portion 103 of member 101; and a bore portion 106 that is of a substantially smaller diameter than bore portion 105. As may be noted from FIGURE 10, bore portion 106 opens through the conical end portion on the injector nozzle.

A mixer member 107 is provided in the adapter in abutting relationship with the conical tip of the injector nozzle, the mixer member having a generally conically recessed portion that in conjunction with the conical tip of the injector nozzle forms a passageway 108 surrounding the forward end portion of said tip and opening into the space axially between bore 106 and bore 109 of the mixer member. Bore 109 is of substantially larger diameter than bore 106 and axially aligned therewith. The mixer member is also provided with a generally radially extending bore 37 that places the radial bore 50 of the adapter in fluid communication with the passageway 108.

Mixer member 107' has a reduced diameter forward end portion that seats in the enlarged diameter bore portion of the diffuser 112, the forward end portion of the diifuser abutting against the shoulder (not shown) of the adapter such as has been described with reference to the first embodiment. The diffuser 112 has a frusto-conical shaped mixing bore 115 that at its minor base end opens directly to the forward end of bore 109 and is of substantially the same diameter. The angle of divergency of bore 115 advantageously is the same as that described with reference to bore 34.

Members 104, 107 are wear resistant material such as stainless steel or carbide, while members 101, 112 are made of a cheaper material.

The adapter 32 mounts a hopper mounting body 114, a nut such as nut 47 of the first embodiment being threaded on the forward end portion of the adapter in abutting relationship of said body for retaining a body shoulder in abutting relationship with a shoulder provided on the adapter. As may be noted from the drawings, the hopper mounting body 114 is not provided with any depending boss such as illustrated in FIGURE 1. The hopper mounting body has a reduced diameter bore 116 that at one end opens to adapter bore 50 and at the opposite end opens to an intermediate diameter bore 117 to form a shoulder. Bore 117 at its opposite end in turn opens to one end of a slightly increased diameter bore 118 to form a shoulder therewith, bore 118 having internal threads 118a more closely adjacent said shoulder than the opposite end thereof.

Mounted within bore 117 and extending axially into bore 118 are a valving tube 120 and a tubular support 119. Tube 120 has a greater axial length than its maximum outer diameter. The valving tube in a relaxed condition has a bore 12% extending therethrough that is of a substantially larger diameter than the diameter of bore 116 to which it opens, and an annular flange 120a that seats against the shoulder provided at the juncture of bores 116, 117. The tubular support surrounds the valving tube other than the annular flange 120a and has one end abutting against said annular flange. The annular flange abuts against the shoulder formed at the juncture of bores 116, 117. The tubular support has an exterior surface in aubtting relationship with the inner peripheral wall of bore 117.

Located within bore 118 is a tubular mount 122 that has exterior threaded portion with threads that form a matching fit with threaded portion 118a and an edge abutting against the shoulder at the juncture of bores 117, 118. The tubular mount at its upper end Portion has interior threads that form a matching fit with the exterior threads of the lower end portion of sleeve 123. The interior surface of the tubular mount intermediate its interior threads and the edge that abuts against the shoulder at the juncture of bores 117, 118 is smooth and surrounds the metering valve member 63 and an annular thrust member that is made of rigid material such as metal. The metering valve member has one end portion in abutting relationship with sleeve 123 and an opposite edge portion in abutting relationship with the enlarged diametric portion of thrust member 125. The thrust member has a reduced diameter portion extended into the upper end of the valving tube to form a close fit therewith, and a shoulder formed at the junction of its large diametric and reduced diametric portion that abuts against the upper edges of the tubular support and the valving tube. The thrust member 125 prevents powder moving between the adjacent surfaces of bore 117 and the tubular support 119; and between the surfaces of the valving tube 120 and the tubular support. Also the thrust member prevents forces being transferred from the metering valve to the valving tube that would tend to restrict the opening through the valving tube. The reduced diameter end portion of the thrust member also provides support for the valving tube, particularly when the valve tube is pinched to a powder flow blocking condition.

The thrust member has a constant diameter bore 126 that opens to the bore of the valving tube and is of a substantially smaller diameter than bore 120b, bore 126 also opening to metering valve bore portion 64a. Bore portion 640 of the metering valve opens to the frustoconical end portion of bore 128 of the sleeve 123. Other than for the frusto-conical end portion of bore 128, bores 128, 126 and 116 are of the same diameter. Bore 128 at its uper end opens to the minor base end of the frustoconical bore 129 of sleeve 123, the major base end of bore 129 in turn opening to the enlarged diameter bore 130 of said sleeve to provide a shoulder 131.

A powder hopper 132 having a generally conical lower end portion extended axially into bore 130 is mounted on sleeve 123. The apex portion of the hopper is provided with an outlet 135 that is in axial alignment along axis MM of bores 116, 120b, 126, 128, 129 and 130 and the apex portion of the baflle 137 that is mounted in bore 130.

The baflle has an annular, axially extending, peripheral flange 137a, one edge of said flange seating against shoulder 131 and the opposite edge of the flange being integrally joined with the conical tip portion 137b. The outer peripheral portion of the baflle is provided with a plurality of circumferentially spaced cutouts which form powder passageways 140 to permit powder to flow from within bore 130 to bore 129; said cutouts extending through portions 137a and 137b, As may be noted from FIGURES ll, 13 the smallest transverse dimension between diametrically opposed passageways 140 is substantially greater than the inside diameter of the hopper outlet 135, and the apex portion of the baflle is axially spaced from said outlet.

The sleeve 123 is provided with a plurality of vent apertures 141 corresponding to vent apertures 56, vent apertures 141 being axially more remote from shoulder 131 than the hopper outlet 135. The apex of the baffle is sufliciently close to the outlet 135 such that in a valving sleeve closed condition, the path of travel of the gas upwardly through the bafile cutouts and along the surface of the baflle toward the hopper outlet is substantially greater than the axial path of travel of the gas, from said cutouts to adjacent the vent apertures. This substantially minimizes the likelihood of gas flowing to and through the hopper outlet into the hopper.

A tubular shield 142 is mounted on the sleeve 123, the shield having axially intermediate, internal threads that form a matching fit of the external threads on the sleeve that are generally radially opposite the baflle. As may be noted from the drawings, the inside diameter of the shield axially upwardly of its threads is sufficiently greater than the outside diameter of the radially opposite portion of sleeve 123 to provide an annular clearance space 143. The vent apertures 141 place the interior of the sleeve 123 in fluid communication with the annular clearance space. Since both sleeve 123 and shield extend axially upwardly above the vent apertures a substantial distance, any gas passing through the vent apertures in the clearance space or backfire flames is directed upwardly alongside the exterior surface of the hopper.

The hopper has a snap on cover 145, the cover having a reduced diameter, axially outwardly extending portion 145a on which there is a friction fit cap 145b. When it is desired to pour powder into the hopper, the cover 145 is removed, while after the powder spraying operation has been completed, the cap may be removed whereby powder may be poured through portion 145a into a suitable container. Thus the cover provides a funnel that may be used for pouring powder back into the container, it being undesirable to leave the powder in the container for a period of time due to the fact that the powder is hygroscopic.

To operate the valving tube to a closed condition, the hopper mounting body is provided with an aperture 147 extended radially relative axis MM to open to bore 117 about midway between the opposite axial ends of the valving tube while the support tube is provided with an aperture 148 that is aligned with aperture 147. The reduced diameter portion of elongated plunger 149 is slidably positioned in apertures 147, 148 to have its one rounded end bear against the valving tube and to have its opposite head end loosely pivotally mounted on the transversely extending pivot pin 151. The opposite ends of pin 151 are secured to the generally central portions of the depending legs 153a of the handle 153, the web portion of the handle having a notch in order to permit the handle legs extending along transverse opposite sides of the hopper mounting body. The lower ends of the legs 153a are pivotally connected to the hopper body by a transverse pivot member 154. A spring member 156 has its one end secured in the hopper mounting body and a portion bearing against the web of the handle for resiliently retaining the handle in a position that the plunger 149 retains the valving tube in a closed condition.

The support tube 119 has a slot 158 provided in its outer surface that extends the axial length of said tube, aperture 148 opening to said slot. The plunger is of a length and is mounted by the handle in a manner that when the handle is pivoted in direction of the arrow 159 about pivot 154 to its maximum depressed condition, the rounded end of the plunger will have been completely retracted through aperture 148 but is located in slot 158. As a result, even when the handle is in the depressed condition, the support tube cannot be rotated about axis MM; however, it is possible to axially remove the support tube from bore 117. Thus the slot 158 serves as a keyway in aligning the support tube when the powder torch is being assembled.

The shield 142 is provided with a cutout 161 opening toward the hopper mounting body while a pointer 162 extends upwardly into said notch to point to indicia along circumferential edge of the notch in the manner described relative the pointer 87 in notch 88b of the first embodiment. A screw 163 secures the lower end of the pointer to the hopper mounting body.

By manually rotating shield 142 about the axis MM, the degree of compression of the metering valve and thereby the minimum cross-sectional opening therethrough may be changed in a manner corresponding relative the first embodiment. However, any rotation of the thrust member that may be caused by rotating shield 142 and therethrough sleeve 123, and the metering valve, the rotary movement of the thrust member does not cause the sup port tube to rotate, even when the handle is in depressed condition, since the plunger extends into slot 158.

The structure of the invention having been described, the operation of the first embodiment will now be set forth. In using the invention, with the handle in the valve shut off position of FIGURE 2, the hopper 55 is filled with suitable powder. In filling the hopper, the powder will flow down through the outlet 55d to fall on the baflie conical portion, thence flow along the surface of conical portion through the passageways 71 into bore portions 66b and 66a, and the flow through bore portion 64 and into the valving tube to an elevation that the tube is squeezed shut. When the hopper is at least partially full, there will be powder within bore portion 53a including in contact with the surface of the peripheral wall defining bore portion 53a to a level up to the lower end of outlet 55d. However, the upper level of powder is below the lowermost edges of apertures 56.

Now the oxygen valve 14 is opened to permit a flow of oxygen through passageway 13 into bore 12 and thence through nozzle bore 25 and member bores 23, 29, the diffuser bore, the bore of adapter 40 and outwardly to the tip. Also the combustible gas control valve 16 is turned on so that fuel gas will blow through bore 15 thence into the annular groove 16 and apertures 26, and

1 1 thereafter into passageway where it mixes with the oxygen to thereafter flow forwardly to tip 43. The mixed gases in flowing through the reduced diameter bore 29 and thence to substantially larger diameter bore 34 and forwardly thereof results in an aspirating effect to passageway 36. However, no powder is drawn into passageway 36 at this time since the valving tube is being squeezed to a shut off valve closed condition. After there is a flame at tip end 43, the handle is pivoted about the pivot 80 to move the pin sleeve 79 to the valving tube open position of FIGURE 3, and thence in part through gravity and in part through the vacuum being applied to passageway 37, powder flows downwardly through the reduced diameter portion 60a of the valving sleeve, into bores 50, 37 and into the passageway as to come in contact with the mixed gas stream and entraine'd in the gas stream as the gas exits from bore 29. The powder is thoroughly mixed with the mixed gases in the diffuser 31.

One of the features of the invention is the provision of a safety vent for gases. This is, in the event that fuel gas or mixed gases should collect in passageways 36, 37 and flows upwardly through the valving tube, the metering valve and into the baflie mount bore, due to the central section of the baffle being of solid cross section, the gases are directed radially outwardly relative axis HH to flow upwardly adjacent the peripheral wall defining bore portion 660, through passageway 71, along peripheral wall 53a, and thence out through the vent openings 56 and thereafter upwardly through the annular space 57 to the ambient atmosphere at an elevation above the upper terminal edges of shield 58 and sleeve 53. In this connection, it is to be noted that the portion of the shield surrounding annular space 57 is imperforated, the terminal edges of shield 58 and sleeve 53 being located in the same plane. Since the cross sectional area of the annular space 57 and also of the apertures 56 is substantially greater than the cross sectional area of the outlet 55d, only a very minor amount, if any, of the gases will flow upwardly into the hopper outlet. In the event some fuel gas or mixed gas flows into the hopper, such gas can escape through the hopper vent opening 55b.

In the event that a back fire should occur, which is most likely to happen when the powder hopper is almost empty, due to the provision of a baifile in the powder passageway from the hopper to the diffuser, the back fire explosive forces move upwardly into the baiflle mount and are dispersed due to the progressively increasing area of bore portion 66b and cannot move directly along the line H-H into the hopper outlet. Rather, due to the imperforate'd central portion of the baffle, such explosive forces are directed radially outwardly to flow through passageways 71 and thence directed so that they primarily move in an axial direction up into the area between the exterior surface of conical portion of the hopper and apertures 56 to be vented through the apertures 56 and upwardly through the annular space 57 to the atmosphere. Thus the back flash forces are directed to the vent apertures rather than through the powder chamber outlet. Additionally, through the provision of the shield at 58, such back flash forces are directed in an upward direction, thereby minimizing the chance of injury to the hand of the operator that is holding the torch. That is, the shield directs any flames resulting from back fire upwardly and away from the operators hands.

Another feature is provision of the diffuser at the location of mixing powder with the mixed gases. The diffuser allows more back pressure at the tip end of the torch and thereby maintains a venturi effect for aspirating the powder from the powder passageway. The diffuser compensates for back pressure resulting from restrictions downstream of the injector by controlling the expansion of the gas stream from the small thrust section thereof to the larger chamber in the torch tip. Thus a diffuser has greater efliciency of ejection, and through the use thereof there is an increase in pounds of product that can be 12 sprayed per hour from that if this diffuser was not provided.

Preferably the diffuser 31 is made of stainless steel or carbide and has an included angle of divergence D of about 4-10". Also it is preferable that the mixed gas conducting member 17 be made of stainless steel, ceramic, or Monel (an alloy of about 67% Ni; 30% Cu; 1.4% Fe; 0.1% Si and 0.15% C). We have discovered that by making member 17 (also member 104) of, for example, stainless steel instead of, for example, brass, the powder torch has a substantially higher degree of back fire resistance. The explanation for this improved resistance to back fire is not known. However it is believed that when member 17 is made of materials such as brass, the brass member heats sufficiently that upon powder moving into bores 23, 20 from a back fire, the powder adheres to the bore' walls. The adhering powder may be sufliciently hot to reignite the mixed gases in bores 23, 29 and/or sufliciently block the bores to cause turbulence in the bores which results in a condition for more frequent occurrence of back fire.

As an example of dimensions of a diffuser having an angle D in the preferred range and not otherwise as a limitation on the invention, a diffuser may have a bore 34 of an axial length L of about 1 /2", :1 minor base diameter M of about 029-096" and a major base diameter of about Vi and a cylindrical bore 33 of an axial length C of about /2".

It is believed that the operation of the second embodiment is clear from the preceding description. However, it is to be mentioned that the tubular mount 122 is sulficiently tightly threaded into the hopper mounting body and the shield threaded onto the sleeve 142 that when the shield is rotated, sleeve 142 rotates therewith and relative mount 122 to vary the axial compression of the metering valve within limits as has been described relative the first embodiment.

As has been previously indicated, one of the features of this invention is the gas venting feature. In FIGURE 15, wherein the baffle mount 200 may be the same as member 53, 67 of the first embodiment; and baflle 201 the same as either baffle or baflle 137 and the hopper outlet 204 the same as that of either the first or second embodiment, the baffle 201 directs any back flow of gases to the inner peripheral Wall of baflle mount 200 to vent through apertures 202', i.e. the flow path indicated by arrows 205. As may be noted from FIGURE 15, the portion of flow path 205 from the location of the back flow of gases passing upwardly of the baffle cutouts to the location the gas has passed through the powder is indicated by the dimension S; while the portion of the flow path 208 that the back flow of gases would take through the powder to flow into the hopper inlet 204 of hopper 203 is indicated by the dimension R. Since dimension R is substantially greater than dimension S, the path to the atmosphere is drastically shorter and easier along path 205 than path 208. With powder in the hopper, this feature virtually eliminates the possibility of mixed gases getting into the hopper.

What is claimed is:

1. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, and baffle means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said baflle means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet, said first means having a vent aperture opening to the powder passageway axially remote from the intersection of the powder passageway with the one of the other passageways for venting gas to the ambient atmosphere.

2. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, first means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a first powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, a tip section, and second means for connecting the first means to the tip section to conduct mixed gases and entrained powder to said tip section, a powder hopper having a hopper outlet, third means mounted on the torch member for mounting the powder hopper and having a second powder passageway for conducting powder flowing through the hopper outlet to said first powder passageway, said third means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, said third means including an axially elongated sleeve forming a part of said second powder passageway and having an end portion remote from said second means, said sleeve end portion having a terminal edge, said hopper being mounted on said end portion to have its outlet open within the sleeve substantially more closely adjacent said second means than said sleeve terminal edge and to extend a substantial distance outwardly of said sleeve in an axial direction relative the direction of elongation of said sleeve, said sleeve having at least one vent opening axially intermediate the hopper outlet and said sleeve terminal edge, and having an inside diameter adjacent said hopper that is substantially greater than the diameter of said hopper outlet, and a tubular shield mounted on said sleeve in at least partial surrounding relationship to said sleeve, said shield having one terminal edge axially inwardly of said vent opening, said shield and sleeve cooperatively having a vent clearance space that opens to said vent opening, and to the ambient atmosphere adjacent to and exteriorly of the hopper for directing any explosive force passing through the vent opening along the exterior surface of the hopper in a direction axially away from said sleeve.

3. The apparatus of claim 2 further characterized in that the hopper has a conical portion extending into the sleeve, joined to said hopper outlet and conveying in a direction toward said hopper outlet, and that said sleeve has several vent openings opening to said clearance space, the cross-section area of said hopper outlet opening being substantially less than the area of the vent openings, and the vent openings being axial more closely adjacent said opposite terminal edge than said hopper outlet.

4. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a first powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gas end entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and providing a second passageway to conduct powder flowing through the hopper outlet to said first powder passageway, said first means being elongated in an axial direction extending at an inclined angle to the direction of elongation of the torch member and having an axially elongated opening therein, valving means operable between a first open condition to permit the flow of powder therethrough and a second condition to block the flow of powder therethrough, an axially compressible, resilient metering valve having an axially extending bore therethrough, said valve and valving means being within said opening, second means mounted on said torch member to mount said valving means and metering valve, and third means mounted on the second means for selectively varying the axial compression of said metering valve to adjust the cross-sectional area of the metering valve bore, said valving means in an open condition and the metering valve bore forming parts of said second powder passageway, and hand operable means mounted on the first means for operating the valving means between its first and second conditions.

5. The apparatus of claim 4 further characterized in that said second means includes a boss having a central axis extending at said angle, a first bore portion and a second bore portion of a reduced diameter that opens to said first bore portion to form a shoulder, said metering valve being mounted in said first bore portion in abutting relationship with said shoulder, that said metering valve is of a shorter axial length than said boss first bore portion, that said third means comprises a baflle mount having a reduced diameter portion movable extended into said boss first bore portion, said baffle mount having a bore axially aligned with the hopper outlet and the metering valve bore, said batfle mount bore having a reduced diameter bore portion opening to said metering valve, an axially intermediate frusto-conical bore portion having a minor base opening to the last mentioned reduced diameter bore portion and a major base, and a cylindrical bore portion opening to the major base, and a baffle mounted in the cylindrical bore portion and having an imperforated section extended transversely axially between the hopper outlet and the bafile mount reduced diameter portion, and peripheral passages for permitting powder from the hopper outlet into the baflle mount bore, said third means having a vent opening axially outward of the baflle for venting gas flowing through the bafile passage axially toward hopper outlet.

6. The apparatus of claim 4- further characterized in that said second means includes a boss having a threaded portion, that said third means has an end portion threaded on said boss portion, an exterior notch opening toward the boss, and circumferentially spaced indicia adjacent the notch, and that there is provided a pointer having one end portion secured to the boss and extending within the notch toward said indicia.

7. The apparatus of claim 4 further characterized in that the first mentioned means includes means for conducting the mixed gas, the mixed gas conducting means having a conical tip diffuser means for aspirating the powder and mixing the powder with the mixed gas, the diffuser means having a conical recessed portion, and means for mounting the diffuser means and the mixed gas conducting means with the conical tip adjacent the conical recessed portion to provide a clearance space and the diffuser means intermediate the tip and the mixed gas conducting member means, said conical tip and recessed portion forming a part of the first powder passageway, said mixed gas conducting means having a bore opening to said clearance space and said diffuser means having a larger diameter cylindrical bore opening to said clearance space and a diverging bore having a minor base end opening to said cylindrical bore and a major base end remote from said cylindrical bore, the diffuser means and mixed gas conducting means bores forming a part of the mixed gas passageway.

8. A powder torch comprising a torch body having a pressurized oxygen passageway and a pressurized combustion supporting gas passageway, first means mounted on the torch body for receiving gases from the aforementioned passageways and mixing said gases, said first means having a passageway for conducting the mixed gases away from the torch body, a powder hopper having an out let, second means mounted on the first means for mounting the hopper and having a powder passageway extending from said hopper outlet, said first and second means having cooperating means for fluidly connecting the powder passageway to the mixed gas passageway, a torch tip having a passageway, and means for connecting the torch tip passageway to the mixed gas passageway downstream of the powder passageway, said second means including a hopper mounting body having an elongated bore portion intermediate the hopper and the cooperating means and means mounted by the hopper mounting body and extending at least partially within the aforementioned bore portion for blocking the flow of powder from the hopper to the mixed gas passageway and alternately permitting the flow of powder to said mixed gas passageway, said cooperating means including elongated means for conducting mixed gases, said mixed gas conducting means having a conical tip remote from said oxygen and combustion supporting gas passageway, and a reduced diameter bore portion opening through said conical tip and forming a part of the mixed gas passageway, means for mixing and diffusing the powder and mixed gases, said diffuser means having a conically recessed end portion cooperating with the said conical tip to form an intersection between the powder passageway and the mixed gas passageway that opens to said reduced diameter bore portion, and means for mounting the diffuser means and mixed gas conducting means with the conical recess adjacent the conical tip, said diffuser means having a cylindrical bore opening to the intersection between the powder passageway and the mixed gas passageway in axial alignment with said reduced diameter bore portion and axially spaced therefrom and a diverging bore por tion having a reduced diameter end portion opening to said cylindrical bore portion opposite said powder passageway portion, said diverging bore portion has an included angle of divergence in the range of 410, said cylindrical bore portion and diverging bore portion forming a part of the mixed gas passageway intermediate the tip section and the reduced diameter bore portion.

9. The apparatus of claim 8 further characterized in that at least said conically recessed end portion of the diffuser means is made of stainless steel and that at least the conical tip of mixed gas conducting means is made of a material selected from the group consisting of stainless steel, a nickel-copper alloy and ceramic.

10. The apparatus of claim 8 further characterized in that said diffuser means comprises a diffuser having said diverging bore portion and a tubular member having said cylindrical bore portion and conically recessed portion seated against said diffuser, and that said mixed gas conducting means includes an injector nozzle having said conical tip.

11. The apparatus of claim 8 further characterized in that said diffuser mounting means has a bore portion forming part of the cooperating means, that said hopper mounting bore portion has a reduced diameter bore of a substantially larger diameter than said diffuser mounting means bore portion and opening thereto, and a larger diameter bore opening to the reduced diameter bore opposite the diffuser mounting means, and that powder flow blocking means includes a valving tube having a reduced diameter portion extending within the last mentioned reduced diameter bore into fluidly sealing engagement with the diffuser mounting means and a larger diameter portion within the larger diameter bore in a fluid sealing engagement with the peripheral wall defining the last men tioned bore, said tube having a bore opening to the diffuser mounting means bore for powder to flow through.

12. A powder torch comprising a torch body having an oxygen passageway and a combustion supporting gas passageway, first means mounted on the torch body for receiving gases from the aforementioned passageways and mixing said gases, said first means having a passageway for conducting the mixed gases away from the torch body, a powder hopper having an outlet, second means mounted on the first means for mounting the hopper and having a powder passageway extending from said hopper outlet to one of the prior mentioned passageways, a torch tip having a passageway, and means for connecting the torch tip to the second means and fluidly connecting the torch tip passageway to the mixed gas passageway downstream of the powder passageway, said second means including a hopper mounting body having an elongated bore portion intermediate the hopper and the mixed gas passageway and an axially elongated valving tube in said bore portion, the interior of said tube forming a portion of said powder passageway, an axially elongated tubular support within said bore portion and surrounding a major portion of said valving tube to retain said tube in compression, said tubular support having a first support edge, a second support edge axially opposite the first support edge and axially more closely adjacent the hopper than the first support edge, an axially elongated keyway slot extending to the first support edge and a plunger aperture opening through said tubular support to the tube and to the keyway slot axially remote from said first support edge, a plunger slidably movable in said aperture between a position holding the valving tube closed to block flow of powder therethrough, and a position out of said aperture and extending within said keyway slot, and hand operable means mounted on one of said bodies for operating the plunger between its position.

13. The apparatus of claim 12 further characterized in that said hopper mounting body has a second bore portion of a substantially smaller diameter than the first mentioned bore portion opening to the valving tube interior and the first bore portion axially remote from the hopper to form a first shoulder, a third bore portion opening to the first bore portion opposite the second bore portion, said valving tube having a radially outwardly extending flanged end portion abutting against said first shoulder, said tubular support having an end portion abutting against said flange, and that said second means includes a thrust member in said third bore portion abutting against said valving tube and the tubular support, said thrust member having an annular flange extending axially within said valving tube, and means for retaining said thrust member in abutting relationship to said valving tube and tubular support.

14. A powder torch comprising an elongated torch member having a pressurized oxygen passageway, a pressurized combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gas and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated in an axial direction extending at an inclined angle to the direction of elongation of the torch member and having an axially elongated opening therein for conducting powder to the powder passageway, said first means including a hopper mounting body having an axially elongated bore portion intermediate the hopper outlet and the powder passageway and a cutout intersecting said bore portion, and valving means in said bore portion for selectively blocking the flow of powder to said powder passageway and alternately permitting the flow of powder to said powder passageway, said valving means including an axially elongated, resilient valving tube in said bore portion to have powder pass therethrough, and hand operable means mounted for operating the valving means, said hand operable means including means for squeezing said tube to block the flow of powder therethrough, the last mentioned means including elongated annular resilient means extending in said cutout that is elongated in direction transverse to the direction of elongation of said torch member, a transverse metal pin extended through said annular means and pivotally mounted hand operated means for mounting said annular means and moving said pin and thereby the annular means against the valving tube to block the flow of powder therethrough.

15. A powder torch comprising a torch body having an oxygen passageway and a combustion supporting gas passageway, first means mounted on the torch body for receiving gases from the aforementioned passageways and mixing said gases, said first means having a passageway for conducting the mixed gases away from said torch body, a powder hopper having an outlet, second means mounted on the first means for mounting the hopper and having a powder passageway extending from said hopper outlet to one of the prior mentioned passageways, a torch tip having a passageway, and means for connecting the torch tip to the second means and fluidly connecting the torch tip passageway to the mixed gas passageway downstream of the powder passageway, said second means including a hopper mounting body having an elongated bore portion intermediate the hopper and the mixed gas passageway and an axially elongated resilient valving tube in said bore portion, the interior of said tube forming a portion of said powder passageway, said hopper body having a cutout intersecting said bore portion, means for squeezing said tube to block the flow of powder therethrough and alternately permitting the flow of powder therethrough, the last mentioned means including a resilient member extending in said cutout, and hand operated means pivotally mounted on said body for mounting said resilient member and selectively moving said resilient means into abutting relationship to valving tube to block the flow of powder therethrough.

16. The apparatus of claim further characterized in that a rigid sleeve is mounted on said tube radially intermediate the valving tube and the bore portion peripheral wall, said sleeve having a cutout of a size and shape for the resilient member to be moved therein against the valving tube to block the flow of powder through said tube.

17. The apparatus of claim 16 further characterized in that said cutout has an edge, that said hand operated means includes a metal pin extended through said resilient member and hand lever means pivotally mounted on said body for mounting said pin for movement therewith into abutting relationship with said edge when the resilient means bears against the valving tube to block the flow of powder to limit the pivotal movement of the said pin in a direction toward said tube.

18. The apparatus of claim 17 further characterized in that the first means includes an axially elongated gas mixing member having a generally conical tip axially remote from said torch body, an axially intermediate portion, a reduced diameter bore opening through said conical tip, a larger diameter bore having one end opening to said reduced diameter bore and an opposite end, means cooperating with gas mixing member for receiving gas from the oxygen passageway and the combustion supporting gal; passageway, mixing said gases and conducting the mixed gases to the opposite end of the larger diameter bore, said second means including a generally annular membelt having one end portion mounted on said gas mixing member intermediate portion, a diffuser mountingly retained im the annular member opposite end portion, said diflusen having an end portion cooperating with said conical tip tc. provide a clearance space surrounding at least a portion oi the conical tip including a passage opening from the clearance space to the exterior surface of the diffuser, said reduced diameter bore opening to said clearance space, said diffuser having a cylindrical bore of a substantial larger diameter than that of the reduced diameter bore in axial alignment therewith that at one end opens to said clearance space and a bore that opens to said cylindrical bore axially remote from said clearance space and diverges in an axial direction away from said cylindrical bore, the diffuser bores forming a portion of the mixed gas passageway, said hopper mounting body being mounted on said annular member, and said annular member having a bore opening to said passage and to said body bore portion, the annular member bore and the clearance space constituting a portion of the powder passageway.

19. The apparatus of claim 18 further characterized in that said body bore portion has a first diameter bore portion and a second diameter bore portion of a substantially smaller diameter than the first bore portion that opens through to form an annular shoulder, said second bore portion being of a substantially larger diameter than the annular member bore and opening thereto, and that said valving tube has an enlarged diameter portion in said first diameter bore portion seating against said shoulder and a reduced diameter portion integrally joined to the enlarged diameter portion and extending through said second bore portion into sealing engagement with said annular member, said reduced diameter portion opening to the annular member bore.

20. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated in an axial direction at an angle to the direction of elongation of the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, and baffle means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire through the valving means to the hopper outlet, said first means including axially elongated second means for mounting the bafile means and hopper in axial spaced relationship and conduct the flow of powder over said bafl'le means and toward said powder passageway, said second means having a vent aperture more axially remote from the bafiie means than the baflle means is axially spaced from the hopper outlet for venting gas from the region between the baflie means and the hopper, said baflle means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet located axially between the valving means and the hopper outlet, said imperforated portion having a surface adjacent the hopper outlet that extends both upwardly toward said hopper and transversely away from said vent aperture whereby the portion of the gas flow path through the powder toward the vent aperture is of a shorter distance than the portion of the gas flow path through the powder to the hopper outlet.

21. The apparatus of claim 20 further characterized in that said imperforated portion is conical and has an apex portion located in axial alignment with the hopper outlet and more closely adjacent the hopper outlet than the remainder of said imperforated portion, and that a shield is mounted on the second means to direct any gases flowing through the second means and outwardly through the vent aperture upwardly toward the hopper to vent to the ambient atmosphere.

22. The apparatus of claim 4 further characterized in that the first means includes cooperating means, in part connected to the second means, to indicate the degree of axial compression of the metering valve and thus the rate of powder flow.

23. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, and baffie means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said baffle means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet, said baffle means comprising a bafile mount having a reduced diameter bore portion and a frusto conical bore portion having a minor base opening opening to the reduced diameter bore portion, and a major base opening, said reduced diameter bore portion being more axially adjacent the valving means than the major base opening and a battle having said imperforated portion, said battle and baffle mount cooperatively having a powder passage to permit the flow of powder into said frusto conical bore portion, said baflie means bore portions and powder passage being provided to conduct powder intermediate the hopper and the powder passageway.

24. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion sup porting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, said first means including an axially elongated sleeve having an end portion axially remote from said valving means, said hopper having a conical portion in abutting relationship with said sleeve end portion extending axially both without and within the sleeve, and being joined to said sleeve, said hopper outlet being within the sleeve, said sleeve having radial vent apertures opening therethrough axially between the hopper outlet opening and said sleeve end portion, and a shield mounted on the sleeve, said shield being imperforated radially opposite said vent apertures, said shield and sleeve cooperatively having a clearance space opening to said vent apertures and to the ambient atmosphere adjacent said conical portion for directing back fire and mixed gases axially relative said sleeve after passing through said apertures, and baifle means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direction line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said baflie means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet.

25. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated ope ing therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, said valving means comprising an axially elongated, resilient valving tube having an axially elongated bore for powder to flow through, said first means having a cutout opening to said valving tube, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, said handle means including an elongated resilient valve sleeve extended in said cutout and hand operated means mounted on said first means for mounting said valve sleeve and selectively moving said valve sleeve against the valve tube to squeeze the valve tube to block the flow of powder therethrough and alternatively in a direction relative the valve tube to permit the flow of powder therethrough, and baflie means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said baflie means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet.

26. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, baflle means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said baflle means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet, and a resilient metering valve having an axially extending bore therethrough for powder to flow through, said first means including an annular metering valve mounting portion having an internal shoulder axially between said valving means and said batfle means, said metering valve being mounted within said annular portion in abutting engagement with said shoulder, said first means including means movably mounted on said annular portion for mounting said baffle means in abutting relationship with the metering valve and selectively moving the baflie means to axially compress said metering valve to reduce the cross-sectional area of said bore, said bore providing a powder passageway portion within said first means.

27. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, and baflle means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said baflle means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet, said first means including an elongated mixed gas conducting member having a conical tip remote from said oxygen and combustion supporting gas passageways, the last mentioned member having a reduced diameter bore portion opening through said conical tip and forming a part of the mixed gas passageway, a diffuser having a conically recessed end portion cooperating with the said conical tip to form a powder passageway portion, the last mentioned portion forming a part of said powder passageway and opening to said reduced diameter bore portion, and means for mounting the diffuser and mixed gas conducting member with the conical recess adjacent the conical tip, said difluser having a cylindrical bore opening to said powder passageway portion in axial alignment with said reduced diameter bore portion and axially spaced therefrom and a diverging bore portion having a reduced diameter end opening to said cylindrical bore portion opposite said powder passageway portion, said cylindrical bore portion and diverging bore portion forming a part of the mixed gas passageway intermediate the tip section and the reduced bore portion.

28. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gases and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and conducting powder flowing through the hopper outlet to said powder passageway, said first means being elongated to an axial direction at an angle to the direction of elongation in the torch member and having an axially elongated opening therein, valving means mounted in the first means for selectively blocking the flow of powder therethrough and alternately permitting the flow of powder therethrough, handle means mounted by at least one of the first means and the torch member for operating the valving means in the aforementioned manner, and baflle means mounted in said first means axially between the valving means and the hopper outlet for directing powder flow radially outwardly from a direct line of flow from the hopper outlet to the valving means and to block direct axial movement of mixed gases and back fire from through the valving means to the hopper outlet, said bafile means having an imperforated portion of a substantially larger cross sectional area than the corresponding cross sectional area of the hopper outlet opening axially between the valving means and the hopper outlet, said first means comprising axially elongated second means for mounting the batlle means and hopper in axial spaced relationship and conducting powder flowing toward said powder passageway, said second means having a vent aperture more axially remote of the baffle means than the hopper outlet for venting gas from the region between the battle means and the hopper.

29. The apparatus of claim 28 further characterized in that said second means comprises a sleeve having an internal shoulder facing said hopper and that said battle means includes a slotted, axially extending, annular flange having one edge seated on said shoulder, said flange joined to said imperforated portion in axial spaced relationship to said edge.

30. The apparatus of claim 28 further characterized in that said second means comprises a hopper mounting body boss portion having a threaded portion, an axially elongated sleeve having one end portion threadedly mounted on said threaded portion and an opposite end portion mounting said hopper, and a generally annular bafile mount removably mounted in said sleeve, said bafile mount having an internal shoulder facing said hopper, and that said baflle means is mounted in abutting relationship with said shoulder.

31. The apparatus of claim 28 further characterized in that said first means includes an axially compressible, general annular metering valve having a powder passage therethrough, and third means mounted on the torch member for mounting said metering valve and mounting said second means for limited relative axial movement, said third and second means having surface portions bearing against opposite axial ends of said metering valve to vary the axial compression thereof and thereby vary the cross-sectional area of said metering valve passage as the second means is moved a limited amount relative the third means.

32. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a first powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gas and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and providing a second passageway to conduct powder flowing through the hopper outlet to said first powder passageway, said first means being elongated in an axial direction and having an axially elongated opening therein, valving means mounted on said first means and within said opening for selectively blocking the flow of powder therethrough to the first powder passageway and alternately permitting the flow of powder, said valving means including an axially elongated valving tube having an opening therethrough forming a part of the second powder passageway, and hand operable means mounted on the first means for operating the valving means in the aforementioned manner, said first means including an axially compressible, resilient metering valve having an axially extending bore therethrough forming a part of said second powder passageway, an annular thrust member in the first means opening intermediate the metering valve and the valving means,

said thrust member having an annular flange extending axially within said valving tube and opening within said valving tube, and second means for selectively varying the axial compression of said metering valve to selectively vary the cross-sectional area of the metering valve bore.

33. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a first powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gas and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and providing a second passageway to conduct powder flowing through the hopper outlet to said first powder passageway, said first means being elongated in an axial direction extending at an inclined angle to the direction of elongation of the torch member and having an axially elongated opening therein, and valving means mounted within said opening for selectively blocking the flow of powder there through to the first powder passageway and alternately permitting the flow of powder, and hand operable means mounted on the first means for operating the valving means in the aforementioned manner, said first means including an axially compressible, resilient metering valve having an axially extending bore therethrough forming a part of said second powder passageway, a boss having external threads, and second means for selectively varying the axial compression of said metering valve to selectively vary the cross-sectional area of the metering valve bore, and said second means including an annular member having a surface bearing against said metering valve, the interior of said annular member forming a part of said second powder passageway, and a sleeve having a threaded end portion threadedly on said boss threads, said sleeve having a shoulder bearing against said annular member for retaining the annular member in abutting engagement with the "metering valve.

34. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed gas passageway, and a first powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gas and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and providing a second passageway to conduct powder flowing through the hopper outlet to said first powder passageway, said first means being elongated in an axial direction extending at an inclined angle to the direction of elongation of the torch member and having an axially elongated opening therein, and valving means mounted within said opening for selectively blocking the flow of powder therethrough to the first powder passageway and alternately permitting the flow of powder, and hand operable means mounted on the first means for operating the valving means in the aforementioned manner, said first means including an axially compressible, resilient metering valve having an axially extending bore therethrough forming a part of said second powder passageway and second means for selectively varying the axial compression of said metering valve to selectively vary the cross-sectional area of the metering valve bore, the second means ineluding an axially elongated sleeve forming a part of said second powder passageway and having an end portion remote from the mixed gas conducting means, said end portion having a terminal edge, said hopper being mounted on said end portion and having its outlet open within the sleeve substantially more closely adjacent the metering valve than the terminal edge of said edge portion, said sleeve having at least one vent opening axially intermediate the hopper outlet and said terminal edge, and said hopper outlet being of a substantially smaller diameter than the inside diameter of said sleeve.

35. A powder torch comprising an elongated torch member having an oxygen passageway, a combustion supporting gas passageway, a mixed gas passageway, means for receiving oxygen from the oxygen passageway and combustion supporting gas from the combustion supporting gas passageway, mixing said gases and conducting the mixed gases to the mixed passageway, and a first powder passageway intersecting one of the previously mentioned passageways for conducting powder thereto to be entrained by the gas flowing therethrough, and a tip section connected to said torch member for receiving the mixed gas and entrained powder, a powder hopper having a hopper outlet, first means mounted on the torch member for mounting the powder hopper and providing a second passageway to conduct powder flowing through the hopper outlet to said first powder passageway, said first means being elongated in an axial direction extending at an inclined angle to the direction ofelongation of the torch member and having an axially elongated opening therein, and valving means mounted within said opening for selectively blocking the flow of powder therethrough to the first powder passageway and alternately permitting the flow of powder, and hand operable means mounted on the first means for operating the valving means in the aforementioned manner, said first means including an axially compressible, resilient metering valve having an axially extending bore therethrough forming a part of said second powder passagewaygand second means for selectively varying the axial compression of said metering valve to selectively vary the cross-sectional area of the metering valve bore, said second means including third means mounted on the torch member for abuttingly engaging the outer peripheral wall of said metering valve and an annular portion of one axial end of said meter valve and fourth means rotatably mounted on the third means in abutting engagement with an annular portion of the opposite axial end of said metering valve to in cooperation with said third means vary the axial compression of the metering valve as the fourth means is rotated a limited amount relative the third means, said fourth means having a powder flow path from the hopper outlet to the metering valve bore. e

36. The apparatus of claim 35 further characterized in that said third means comprises a hopper mounting body having an internal shoulder facing said hopper and abutting against the first mentioned annular portion, and threads having a thread axis at said inclined angle, and that said fourth means has a threaded portion forming a matching fit with the first mentioned threads to rotatably mount the fourth means on the third means.

37. The apparatus of claim 36 further characterized in that said fourth means comprises a sleeve having said threaded portion and an end portion axially remote of said threaded portion mounting said hopper, a generally annular bafile mount mounted in said sleeve in abutting relationship with said meter valve opposite end portion and a bafi'le mounted on said bafile mount axially between said metering valve bore and the hopper outlet.

38. The apparatus of claim 37 further characterized in that said third means includes a hopper mounting body having a first bore portion, and a second bore portion of a larger diameter opening to said first bore portion to form a shoulder and extending axially more adjacent the hopper than the first bore portion, said valving means being tubular, axially elongated, and mounted in said first bore portion to extend into said second bore portion, an annular thrust member mounted in the second bore portion and on said tubular valving means to extend thereinto, said thrust member being mounted in abutting relationship with the metering valve one axial end portion and permitting passage of powder from said metering valve bore to the interior of said tubular valving means.

'39. The apparatus of claim 38 further characterized in that said third means includes an annular mounting member extending into said second bore portion in surrounding relationship to said thrust member and metering valve and mounted on said hopper mounting body, said annular mounting member having a threaded end portion axially extending more closely adjacent said hopper than the metering valve, and that the fourth means threaded portion is threadably mounted on said annular mounting member threaded end portion for selectively varying the axial compression of said metering valve a limited amount as the annular means is threadedly moved on said threaded end portion.

40. The apparatus of claim 38 further characterized in that said valving means comprises a flexible valving tube, a rigid, axially elongated tubular support extending within said first bore portion radially between a major portion of said valving tube and the first bore portion peripheral wall, said tubular support having an aperture opening through an intermediate portion thereof, and that the hand operable means includes a plunger slidably extended through said aperture, and means on the torch member for operating said plunger between a position closing said valving tube and a position permitting the valving tube to move to an open condition.

41. The apparatus of claim 40 further characterized in that said tubular support has a keyway slot extending the axial length thereof, that said aperture opens to slot, and that said plunger operating means is operable to retract the plunger to a position out of the bounds of said aperture and within said keyway slot.

References Cited UNITED STATES PATENTS 2,233,304 2/1941 Bleakley 239 2,418,200 4/ 1947 Smith 23985 2,957,630 10/1960 Lamb 23985 3,194,501 7/1965 Cape 23985 3,220,652 11/1965 Cape 23985 3,226,028 12/1965 Schilling 23985 EVERETT W. KIRBY, Primary Examiner 

